I read up about the Keeper, Diva Cup, and so forth. It seemed like the Diva Cup was my best first-try choice, so I went for it. I knew from reading that I was likely to have trouble inserting it, removing it, and lots of leaks on my first go-round, so I prepared myself for that.
To my great surprise, nothing could be easier than using the Diva Cup. It's a cinch to insert (maybe because I'd been using the no-applicator OB tampon intermittently), it seems to move easily into place, and it's as easy to pull out as it is to put in. (I was surprised to see how much I bled today; I thought it was going to be a just-spotting day, but apparently not!) It doesn't touch the cervix, so all my fears of pain are unfounded. I do find a little discomfort with how far the stem hangs down, and it makes me wonder if my vaginal canal is short; the stem seems to end right at my vaginal opening, which means I'm always aware of it. I may cut the stem down at some point, after I see how the next couple of days go.
I'm still on the first day, but so far it's going way more smoothly than I imagined it could. I'd strongly recommend it to my friends.
ETA: Oh, and my cramping is minimal, and normally I'm in agony by now. Score another for the Diva!